This invention relates generally to systems for interlocking two parts, and more specifically, it relates to a part retention system for easily locating and affixing an end cap to a bracket of a slidably adjustable seat position adjuster.
Retaining systems for interlocking mating parts of an assembly play an important role in the manufacture of many everyday items. Such systems are utilized in a wide variety of applications. Many industries, particularly the automotive industry, employ retaining systems to interlock parts of an assembly, secure ancillary components to a larger assembly, and add decorative or trim pieces to various more functional components.
For example, automotive manufacturers often add trim pieces to cover a seat adjuster mounting bracket and bolt. The trim cover enhances the overall appearance of the seat adjuster track, and also covers up any damaging sharp edges or protrusions of the bracket and/or attaching bolt.
Many types of retaining systems are known and disclosed in the prior art. For example, Japanese Patent 3-55331 discloses a retaining system including locking detents which are attached to a non-visible side of a cover. This type of arrangement exhibits two inherent drawbacks: a) unsightly sink marks can appear on the visible surface of a molded part due to the abundance of material concentrated in one area, and b) tolerances must be tightly controlled to maintain appearance and proper fit between the parts.
A retaining system disclosed in Japanese Patent 4-123739 utilizes detents formed on flexible ribs to lock to both sides of a tab. However, the locking tab has a triangular cross-section with a complex shape and the flexible ribs are connected at their ends. Product of this structure requires a complex manufacturing process. A retaining system which incorporates a dual detent locking device is disclosed in Japanese Patent 63-117619. This system requires a mating part having a cut out or separately inserted portion to interlock with a part incorporating the dual detents.
Thus, it would be desirable to provide a retaining system which minimizes the tolerance precision and the amount of material concentrated behind the visible surfaces of molded parts, resulting in cost savings per part. It would also be desirable to provide a retaining system which permits easy installation for areas of low clearance and which is self-locating.
The present invention is directed to a part retainer system for attaching an ancillary part to a component or part of an assembly. The part retainer includes a cap having a pair of flexible guide ribs formed on the inner surface of the cap. Detents extend from the guide ribs to engage a tab formed on the component to which the cap is attached. The guide ribs are deformable. At installation, the guide ribs slide along the tab to permit the detents to pass over the tab. Once the tab passes the detents, the ribs flex toward each other, such that the detents lock the tab in place, resulting in the secure attachment or interlocking of the components.
The present invention alleviates the concern for critical tolerance control, through application of flexible ribs which, by their nature, do not require the strict tolerances of the prior art in order to achieve the same objective. These ribs extend normally along the non-visible surface of the cap, allowing the detents, and their inherent high mass concentration, to be spaced away from the visible appearance-tuned surface. This arrangement reduces the potential in molded parts for unsightly sink marks. Moreover, the need for tight tolerances in the present invention is reduced because an imprecise fit between the guide ribs and locking tab on the mating part would be accommodated by a greater variable spacing between the flexible ribs.
The present invention combines all of the aforementioned advantages while bypassing the difficulties. The present invention incorporates self-locating features, secure retention, and efficient manufacture in a low-cost fashion by integrating the retention system directly into the attached or interlocked parts. The result is a retaining system with reduced costs, both in the manufacture and assembly of the interlocked parts.